Self-adjusting toroidal core support apparatus



R. E.. CRAIG 2,994,487

SELF-ADJUSTING TOROIDAL GORE SUPPORT APPARATUS Aug. 1, 1961 Filed Sept 22, 1958 Moron CONTROL CIRCUIT w mw%e 3 WW u 0 m W a 2 E. M f p Y w A M Mm m 0 MM w W /WZ Wi United States Patent 2,994,487 SELF-ADJUSTING TOROIDAL CORE SUPPORT APPARATUS Robert E. Craig, Sylmar, Califl, assignor to Robert E. Ditrick, Burbank, Calif. Filed Sept. 22, 1958, Ser. No. 762,438 4 Claims. (Cl. 242-4) This invention relates to toroidal core winding machines, and more particularly to improved means for supporting a core for rotation while the winding is wrapped thereon, and which automatically compensates for buildup of the winding to maintain a fixed spacing between the shuttle and the turns placed on the core.

Prior art toroidal core Winding machines are characterized by the fact that turns of a winding are placed on cores with varying spacing. Such problems arise because the cores are rotated at a different speed, for each layer, the object being that as the winding builds up on the core, the turns of each layer are properly spaced. However, it has heretofore been necessary for an operator to manually control the speed of rotation of the core for this purpose. Human errors naturally result in variations in the number of turns per inch on successive layers of a Winding and this obviously afiects the inductance of the completed winding. Accordingly, it has been necessary to use valuable time to check each wound core in order to ascertain its inductance. This is not a precisely controlled factor, and hence high volume production of toroidal windings with uniform characteristics cannot be achieved.

An additional difliculty with prior art winding machines is that, as the winding builds up on the core, the outer turns of the winding may rub against the confronting surface of the shuttle. The accompanying abrasive action weakens the winding structure. Such abrasion also aids in causing the Wire to break under the tension with which they are applied.

Prior art toroidal core windings are not readily adjustable to accommodate the making of windings on cores of a wide variety of sizes. Accordingly, it is often necessary to install several machines, each adapted to Winding cores of a limited number of sizes, all at considerable expense to the manufacturer.

lt is an object of this invention to provide an improved toroidal core support structure, which facilitates the Winding of cores of a wider variety of sizes than is possible with prior art toroidal core winding machines.

It is another object of this invention to provide an im proved toroidal core winding machine in which the space between the shuttle and the portion of the winding being applied to the core is maintained constant, thereby to avoid the possibility of the shuttle and winding rubbing together.

A further object of this invention is to provide roller support means for a toroidal core through which a shuttle rotates to feed wire onto the core at a point adjacent the shuttle, the rollers being adapted to move the core horizontally so that the distance between the shuttle and the adjacent point on which the Winding is placed is maintained constant.

It is yet another object of this invention to provide an improved toroidal core winding apparatus capable of automatic operation for maintaining the same lead for all the turns of the winding.

It is also an object of this invention to provide a toroidal core support apparatus utilizing roller means for supporting the core to prevent it from being dislodged as the winding is built up thereon.

The above. and other objects and advantages of this invention will become apparent from the following description, taken in conjunction with the accompanying drawing of an illustrative embodiment thereof, in which:

FIGURE 1 is a top plan view of space rollers for supporting a toroidal core in accordance with my invention, showing the cooperative relationship between the core and a shuttle for feeding wire thereon; and showing the arrangement of the rollers to effect movement of the core relative to the shuttle as the winding builds up;

FIGURE 2 is a sectional view taken along the line 22 of FIGURE 1, showing the arrangement of the driving roller for rotating the core, and the arrangement of horizontally movable rollers to facilitate moving the core horizontally; and illustrating schematically the operation of motor means to vary the speed of rotation of the core so as to maintain the same lead for all turns; and

FIGURE 3 is a partial top plan view, illustrating schematically the movement of the rollers to cause the core to be moved horizontally so as to keep the same spacing between the shuttle and the point at which the wire is applied to the core.

Referring to FIGURE 1, there is shown a toroidal core 10 supported by three spaced rollers 11, 12, 13 having their axes parallel to the axis of the core 10. One of the rollers 11 is a driving roller for turning the core 10 about its axis, and to this end the roller 11 may be operated by hand crank 14.

Disposed between the other rollers 12, 13 and diametrically opposed to the driver 11, is a shuttle device 15. The shuttle'15, which is of conventional construction, comprises a ring which links the core 10 and is adapted to feed wire onto the core 10 as the shuttle is rotated. It will be understood that the shuttle is driven by a motor as in prior art winding machines.

The tWo rollers 12, 13 are adapted to move horizontally. As the wire is fed from the shuttle 15 to the core 10, the build-up of the wire on the outer periphal surface of the core causes the core to be displaced horizontally from the fixed driver 11. Displacement takes place as each layer of winding is added, and each displacement is equal to the diameter of the wire used.

From the foregoing it will be seen that the space between the confronting surface portions of the shuttle 15 and the core 10 is maintained as initially established. Since the shuttle rotates on a fixed axis, each displacement of the core (equal to the diameter of the wire used) causes the portion of the winding which confronts the shuttle to be spaced the same distance 16 from the shuttle.

FIGURE 3 shows more clearly how my self-adjusting roller mechanism works. The core 10 is initially placed against the fixed driving roller 11, the movable rollers 12, 13 being retracted horizontally to provide clearance for the core while it is being lowered into position. The rollers 12, 13 which are spring biased, are then released so as to move against the core. After the core 10 is positioned between the rollers, the shuttle 15, which is of the split-ring type is linked with the core.

Initially, the shuttle is positioned so that the space 16 between its inner surface and the adjacent portion of the inner surface of the core is the desired spacing required to be maintained throughout the winding operation. As the core is rotated and the shuttle feeds the wire thereon, the rollers 11, 12, 13 bear against the turns of the wire on the outer surface of the core. This means that, since the driving roller 11 is fixed in position, the outer surface of the core 10 will be separated from the fixed roller by the thickness of the layers of the winding. The springbiased rollers 12, 13 move horizontally with the wound core, while being continually biased against the assembly so as to hold it in place.

By the time the winding is completed on the core, the

axis of the core will have moved from an initial position, indicated at 20, to a position 21, and the distance between thepositions 20, 21 of the axis of the core is equal to the thickness of the winding on the core. Meanwhile the rollers 12, 13 will have moved a corresponding distance.

In FIGURE 3, the movable rollers 12, 13 are shown as having initial positions in which their axes are displaced from the axis of the fixed roller 11 by approximately 120. Therefore, the retraction of the rollers 12, 13 as the winding is built up on the core results in the angular distance between the axis of the driving roller 11 and the axes of the rollers 12, 13 being less than 120. It will be recognized that the rollers 12, 13 may be made to move along lines in which the initial positions of the rollers 12, 13 are spaced from the axis of the driving roller 11 by any desired angle, e.g., 160.

Referring to FIGURES l and 2, my rollers 11, 12, 13 preferably are frusto-conical in shape, with the large diameter ends thereof being uppermost. The small diameter ends of the rollers extend from the upper surfaces of enlarged diameter plate elements 11, 12, 13'. By virtue of this arrangement, the plates 11, 12' and 13' provide horizontal ledges or shoulders on which the core (or the winding) sets. As the winding on the core is built up, the outer turns of the winding rest on such ledges, so provided.

The roller 11 is supported on a shaft 25, which at its lower end is journaled for rotation in a base support 26. The upper end of the shaft 25 is of reduced diameter to receive the roller 11, and the roller is suitably keyed to the shaft, as at 27. The upper end of the shaft 25 is rotatably supported in an arm 28 which extends upwardly from the base 26. The shaft 25 is turned by means of meshing gears 30, 31 fixed to the shaft 25 and to the shaft 32 of the crank 14. As shown, the shaft 32 is rotatably mounted in a housing 33 which is secured to the base 26.

The movable rollers 12, 13 are supported by rams 35, 36 which are mounted for horizontal movement in respectrve housings 37, 38, which are secured to respective bases 39, 40. The rams 35, 36 are substantially rectangular block elements, and the housings 37, 38 are pro- ;15deg6with guide slots or channels to receive the rams The supporting structures for both of the movable rollers 12, 13 are the same. Therefore, only the structure associated with the roller 12 (shown in FIGURE 2) will be described in detail; corresponding parts associated with the roller 13, and which are viewed in FIGURE 1, are mdicated by like numbers. I Referring to FIGURE 2, the ram 35 at its inner end 1s substantially U-shaped, thereby to provide opposing arms 45, 46 between which the roller 12 is disposed. For supporting roller 12 between the arms 45, 46, the roller 1s mounted on a shaft 47 which is journaled at its ends in the arms 45, 46.

To bias the roller 12 inwardly, the housing 37 is provided with a rearwardly extending L-shaped arm having one leg 48' extending from one side of the housing, so as to-provide a space between the other leg 48" of the arm and the rear of the ram 35.

Secured in the leg 48" of the arm is a sleeve 49 in which a compression spring 50 is disposed. An adjustable screw 51 is located in the outer end of the sleeve 49. The spring 50 extends into a bore 52 in the ram 35. Thus, when a core is disposed between the rollers, as above described, the screw 51 is adjusted so that the rams 35, 36, and hence the rollers 12, 13 are urged toward the core.

I also provide means for limiting the movement of the rams 35, 36 so that the rollers 12, 13 may not be moved rearwardly against the springs 50, to a point where they may rub against the housings 37, 38. To this end, the rams are slotted within the housings, as indicated at 55 in FIGURE 2, and set screws 56, secured in the housings extend into slots 55. The distance between the forward and rear walls of the slots determines the limits of horizontal travel of the rams, and hence of rollers 12, 13.

To adapt my rollers for supporting cores of a variety of diameters, I mount the bases 26, 39 and 40 on a foundation plate 60. The bases extend at their lower ends into guide channels 61, 62, 63 (see FIGURE 1). The bases are adapted to be secured in place in any position along the channels, as by conventional nut and bolt locking means 65. As will be apparent, the positions of the bases 26, 39 and 40 can readily be adjusted so that the rollers 11, 12, 13 are properly arranged to support substantially any size of core.

The shape of my rollers 11, 12, 13 insures that cores will not become dislodged during the winding process. Since the rollers are frusto conical, and taper outwardly from the lower to the upper ends thereof, the lateral surfaces of the rollers are constantly exerting pressure against the upper edge of the core (or outer layer of the winding). In this manner, I keep the core with the Winding thereon urged against the seats or ledges of the plates 11', 12', 13'. Accordingly, my system insures that the core and its winding will be held in a horizontal position throughout the winding process, and cannot be forced out of a horizontal plane by interaction of the winding and rollers, as is so common in prior art core winding mechanisms.

My invention also provides means for automatically adjusting the speed of the driving roller 11. as the winding is built up on the core, so as to maintain the same lead for the turns throughout the winding process. This, of course, can be done manually by turning the crank 14 properly. However, my invention also incorporates automatic means for this purpose. To this end, and referring to FIGURE 2, I fix a rearwardly extending arm to the ram 35. The arm 70 supports the sliding contact 71 of a potentiometer device 72 which is connected across a D.-C. source, shown as a battery 73. The sliding contact 71 and the grounded terminal of the battery 73 are connected to a motor control circuit 74 for driving'a motor 75 having its output shaft coupled to the shaft 32.

As the ram 35 moves rearwardly due to build-up of the winding on the core, the sliding contact 71 is forced along the potentiometer to cause the motor control circuit 74 to increase the speed of the motor 75, and hence the speed of rotation of the driving roller 11. As will be apparent, any suitable means for providing a variable speed motor can be used, in which the retraction of the ram 35 causes the speed of the motor toincrease. An increase in speed takes place for each displacement of the core, and the control circuit 74 is calibrated to increase the motor speed so that all turns of the winding have the same lead.

Although I have described a particular embodiment of my invention, it will be apparent that numerous modifications may be made without departing from the spirit and scope of my invention. Accordingly, I do notintend that my invention be limited, except as by the appended claims.

I claim:

1. In a toroidal core winding machine in which a shuttle and a magnetic toroidal core are to be rotated on axes at right angles to each other, wherein the shuttle links the core for Wrapping turns of conductive wire thereon, support means for the core to maintain a fixed spacing between confronting portions of the shuttle and the core comprising: a plurality of spaced rollers for engaging the core and holding it in a desired plane, one of said rollers being fixed in position, the remaining rollers being adapted for movement in said plane, said fixed roller being disposed so that, with the core and shuttle in position, the shuttle and said fixed roller are at diametrically. opposed positions about the core; and means to rotate said fixed roller and'elfect rotation of the core about its axis.

2. In a toroidal core winding mechanism wherein a shuttle links a magnetic toroidal core for wrapping turns of conductive wire thereon, means to maintain a fixed spacing between confronting portions of the shuttle and the winding on the core comprising: a plurality of spaced rollers for engaging the core and holding it in a desired plane, one of said rollers being fixed in position, the remaining rollers being adapted for movement in said plane, said fixed roller being disposed so that, with the core and shuttle in position, the shuttle and said fixed roller are diametrically opposed; and means for rotating the core in said plane as the shuttle wraps the turns of wire thereon, whereby the distance between the centers of the core and shuttle is decreased by the thickness of the wire as each layer is wrapped on the core.

3. In a toroidal core winding machine in which a shuttle and a magnetic toroidal core are to be rotated on axes at right angles to each other, wherein the shuttle links the core for wrapping turns of conductive wire thereon, support means for the core to maintain a fixed spacing between confronting portions of the shuttle and the core comprising: three spaced roller elements having vertical axes of rotation, each roller element being generally frusto-conical, said roller elements being oriented with their smaller ends constituting their lower ends, said smaller ends terminating in respective horizontal flanged portions which provide shoulders on which the core rests; respective support means for said roller elements, one support means holding its roller fixed in a position dia- 6 metrically opposed to the confronting portions of the shuttle and core; means biasing the remaining support means toward the core; and means for rotating the roller of said one support means in a horizontal plane.

4. In a toroidal core winding mechanism wherein a shuttle links a magnetic toroidal core for wrapping turns of conductive wire thereon, means to maintain a fixed spacing between confronting portions of the shuttle and the winding on the core comprising: a plurality of spaced rollers for engaging the core and holding it in a desired plane, one of said rollers being fixed in position, the remaining rollers being adapted for movement in said plane, said fixed roller being disposed so that, with the core and shuttle in position, the shuttle and said fixed roller are spaced about the core; means for rotating the core in said plane as the shuttle wraps the turns of wire thereon, whereby the space between the core and shuttle is increased by the thickness of the wire as each layer is wrapped on the core; and means responsive to movement of one of said movable rollers to vary the speed of rotation of the core so that the turns of wire on the core are equally spaced throughout the winding process.

References Cited in the file of this patent UNITED STATES PATENTS 2,726,817 Barrows Dec. 13, 1955 2,727,698 Stevens Dec. 20, 1955 2,793,817 Clarke May 28, 1957 

